Plasma discharges under atmospheric pressure are applicable for modifying the electrical properties of dielectric surfaces. The aim of the plasma discharge treatment of such surfaces is to design a procedure so that its characteristic parameters improve the resulting levels of the breakdown electrical strength E_b when tested under pulsed or alternating electrical voltages. In this research, a set of functional experiments performed by using plasma in samples of two types of materials (thermoset, thermoplastic) were processed and evaluated, and the resulting effect of the magnitude of the breakdown electrical voltage, electrical intensity, and electrical conductivity of the surface were compared. A slit plasma chamber, previously described and parameterized, was employed to treat the surface of the dielectric samples. The surface structure was modified via plasma discharge without precursors, and methodologies were developed to evaluate these modifications with respect to the change in the electrical strength parameters of the insulator surface. Subsequently, the surface strength of the affected and unaffected samples was measured and evaluated as a function of exposure time, and the stability of the modification was assessed. The first methodical test showed that plasma discharge without precursors improved the long-term surface electrical strength of the dielectric surface. The test and its parameters were carried out with respect to feasibility in an industrial environment.

Herein, we discuss the modeling and verification of RF sensed signals in a simple plasma channel (plasma jet) at the generator frequency of f = 13.56 MHz, assuming plasma discharge at atmospheric pressure. The actual experiment was preceded by a basic numerical analysis and evaluation of several variants of the geometric/numerical model of a simple plasma channel formed in a glass capillary chamber; this step was performed with different electrode configurations. The analyses also included the impact of the location of the sensing element (i.e., the antenna) on the resulting evaluated electromagnetic signal. Furthermore, a numerical model with concentrated parameters facilitated a comparative analysis centered on the impact of plasma concentration and composition in the monitored electromagnetic RF spectrum of the channel. The theoretical outputs were verified via experiments and compared. This methodology finds use in the radio-frequency evaluation of plasma parameters in both simple capillary nozzles and more complex, slit-designed plasma chambers.

Plasma discharges under atmospheric pressure can be used to modify the electrical properties of metallic and dielectric surfaces. The aim of such a modification is to achieve an improvement in the characteristic parameters of the surface, for example in the area of the electrical strength of the surface, in order to achieve a higher ultimate level of electrical breakdown E b when tested with pulsed or alternating electrical voltages. So far, research has focused on a set of functional experiments carried out using plasma on samples of two types of dielectric materials (thermoset, thermoplastic) with an impact on the final effect of the level of electrical breakdown voltage, electrical intensity and E b. surface conductivity. The treatment technology requires repeatability and consideration of the industrial deployment conditions of plasma technology. The surface structure was modified in a defined and repeatable way by plasma discharge under atmospheric pressure without the presence of precursors. Methods to evaluate these modifications assessed the change in parameters related to sample type, repeatability and prediction of treatment stability. Subsequently, the surface strength of both the modified samples and the samples not affected by the plasma discharge was measured.

In this paper, the authors describe an electromagnetic–hydrodynamic (EMHD) model of the airborne microbiological agent detection concept for the design of a sensor to identify the presence of airborne bacteria and viruses. Based on the model and a laboratory test, a methodology was proposed for the capture and subsequent detection of low-concentration bacterial and viral agents in airborne aerosols. A physical–biological approach was proposed to detect microorganisms based on their physical properties. The principle was validated in the laboratory on samples of defined concentrated water aerosols of Bacillus subtilis (BS) and feline infectious peritonitis virus (FIVP). Repeated tests with different concentrations were performed in the laboratory conditions.

Plasma discharge at atmospheric pressure can be used to modify the surface electrical strength of insulators made of dielectric materials, thermosets and thermoplastics. The methodology of surface treatment by plasma discharge was published and applied to typical samples of materials with dimensions of 100 × 100 mm. To make the methodological procedure for influencing and predicting the desired change in the dielectric surface industrially applicable, it was necessary to develop a diagnostics methodology for applying plasma discharge at atmospheric pressure. This method was tested on previously selected and tested types of materials on samples of two types (thermoset, thermoplastic). The effects of measuring and evaluating the RF spectrum, along with the corresponding long-term change in the surface strength E_p of the dielectric sample, were demonstrated. This work presents repeated extension tests with statistical evaluation of the effects of surface treatment of dielectric samples using a slot plasma chamber in Ar, N₂ and O₂ atmospheres. The surface structure was modified using precursor-free plasma discharge according to the developed methodologies with the addition of radiometric evaluation of the plasma discharge. Changes in surface properties were measured and evaluated as a function of exposure time and the stability of the modification was evaluated with a prediction of the expected long-term surface properties.